Try wetting one side, let it stand for a couple minutes, it should already start to cup, then apply it with the wet side up. For sharp bends such as turtle decks, you may have to wet it on both sides. You can use a spray bottle or just run it under the faucet. CA glue will work on wet balsa. I have also shaped balsa by wetting it on both sides and wrapping it around something with the curvature you want, such as a pipe or can, then tape it or rubber band it and let dry for a day or so.

This works well for me. Spray one side of the balsa with water then wrap around a spray can or pop bottle and wrap with rubber bands. Whan the wood is dry, it will have a nice curve to it. Mike

I usually find it easier to apply wing sheeting with yellow glue than with CA. Especially the second side, where its nearly impossible to get acces to the sheeting's joints with the ribs.

Repair the broken ribs with thin CA, they should be fine. (normally just split on the grain when they break like that.) sliding the piece in place helps get them lined up so the break is totaly invisible.

Cut the sheeting to fit the location, test fitting several times (easier to cut off a bit more than add some on...)
Just run a thin bead of yellow glue on the ribs. You can CA the front and rear edges, or use yellow glue there too. (Pin the sheet in place before CAing... or run the bead of glue on the edges of the sheet, then pin in place. No difference in construction time.)

There's places for every glue to show its better properties...
CA is too quick for good sheeting jobs, you'll end up with places the sheet isn't stuck to the ribs even with slow set CA. Also the yellow glue gives time to adjust the wing alignment to incorporate proper washout, or ensure the wing is straight (as appropriate.)